Really? That simple? I can think of a couple of other hypotheses that can’t be ruled out based on a chart. Like: European labour market rules that exclude the least-productive (youth, immigrants) also limit hours worked. Or: Leisure is a luxury good.

I didn’t propose a hypothesis and, as you rightly point out, there are many possible causal explanations. It’s not at all surprising that there is a negative correlation between the two. Obviously, a country could be also more productive but still poorer.

However, the chart is a useful antidote to complaints about lazy Greeks and the need for all of Southern Europe to work as hard as the industrious Germans.